6.18-stable review patch. If anyone has any objections, please let me know. ------------------ From: Guangshuo Li [ Upstream commit b167c1a30e9e020e4c5e102c7a555943742c024b ] imx_intmux_probe() enables the IPG clock and then drops its runtime PM reference with pm_runtime_put(). With CONFIG_PM enabled, the runtime suspend callback disables the IPG clock. With CONFIG_PM disabled, the clock remains enabled after probe. imx_intmux_remove() accesses the CHANIER registers without first making sure that the device is runtime active. The device may therefore be runtime suspended with the IPG clock disabled when these registers are accessed. In addition, the remove path only calls pm_runtime_disable() and does not balance the clock enable when CONFIG_PM is disabled. Resume the device and acquire a runtime PM reference before accessing the registers. If resume fails, skip the register accesses but still tear down the chained handlers and IRQ domains. Disable runtime PM afterwards, drop the acquired reference without triggering another runtime suspend, and explicitly disable the IPG clock. This keeps the clock enabled while the hardware registers are accessed and balances the clk_prepare_enable() performed during probe for both CONFIG_PM configurations. This issue was found by manual code inspection. Fixes: bb403111e017 ("irqchip/imx-intmux: Implement intmux runtime power management") Signed-off-by: Guangshuo Li Signed-off-by: Thomas Gleixner Reviewed-by: Frank Li Reviewed-by: Radu Rendec Cc: stable@vger.kernel.org Link: https://patch.msgid.link/20260914134211.1734163-1-lgs201920130244@gmail.com Signed-off-by: Sasha Levin --- drivers/irqchip/irq-imx-intmux.c | 15 ++++++++++++--- 1 file changed, 12 insertions(+), 3 deletions(-) diff --git a/drivers/irqchip/irq-imx-intmux.c b/drivers/irqchip/irq-imx-intmux.c index 5f9b204d350b2..18e214e5b1b59 100644 --- a/drivers/irqchip/irq-imx-intmux.c +++ b/drivers/irqchip/irq-imx-intmux.c @@ -289,12 +289,16 @@ static int imx_intmux_probe(struct platform_device *pdev) static void imx_intmux_remove(struct platform_device *pdev) { struct intmux_data *data = platform_get_drvdata(pdev); - int i; + int i, ret; + + ret = pm_runtime_resume_and_get(&pdev->dev); + if (ret < 0) + dev_warn(&pdev->dev, "failed to resume device: %d\n", ret); for (i = 0; i < data->channum; i++) { /* disable all interrupt sources of this channel */ - writel_relaxed(0, data->regs + CHANIER(i)); - + if (ret >= 0) + writel_relaxed(0, data->regs + CHANIER(i)); irq_set_chained_handler_and_data(data->irqchip_data[i].irq, NULL, NULL); @@ -302,6 +306,11 @@ static void imx_intmux_remove(struct platform_device *pdev) } pm_runtime_disable(&pdev->dev); + if (ret >= 0) { + pm_runtime_put_noidle(&pdev->dev); + clk_disable_unprepare(data->ipg_clk); + pm_runtime_set_suspended(&pdev->dev); + } } #ifdef CONFIG_PM -- 2.53.0